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WEBSTER,  N.Y.  14S80 

(716)  872-4503 


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CIHM/ICMH 

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Microfiche 

Collection  de 

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0 


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I      I    Covers  damaged/ 


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Les  cartes,  planches,  tableaux,  etc.,  peuvent  dtre 
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et  de  haut  en  bas,  en  prenant  le  nombre 
d'images  ndcessaire.  Les  diagrammes  suivants 
illustrent  la  mdthode. 


1 

2 

3 

1 

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<.^> 


[Fkom  the  American  Jouknal  of  Science,  Vol.  XXIII,  February,  1882.] 


CELESTIAL    CHEMISTRY    FROM    THE 
TIME    OF    NEWTON. 


By  T.  Sterry  Hunt,  LL.D.,  F.R.S. 


' 

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[From  the  American  Jouknal  op  Science,  Vol.  XXIII,  Febhuary,  1882.] 


CELESTIAL   CHEMISTRY   FROM    THE 
TIME    OF    NEWTON. 

By  T.  Sterry  Hunt,  LL.D.,  F.R.S.* 


The  late  W.  Vernon  Harcourt,  in  1845,f  called  attention  lo 
the  remarkable  perception  of  great  chemical  truths  which  is 
apparent  in  the  Queries  appended  to  t.he  third  book  of  New- 
ton's Optics,  as  well  as  in  his  Hypothesis  touching  Light  and 
Color.  With  regard  to  the  latter,  Harcourt  then  remarked,  "it 
has,  I  think,  scarcely  been  quoted,  except  by  Dr.  Young,  and 
its  existence  is  but  little  known,  even  among  the  best-informed 
scientifiG  men."  The  essay  in  question  was  read  before  the 
Eoyal  Society,  December  9th  and  16th,  1675,  but  remained 
unpublished  till  1757,  when  Birch,  at  that  time  secretary  to  the 
Society,  printed  it,  not  without  verbal  inaccuracies,  in  tlie  third 
volume  of  his  History  of  the  Royal  Society ;  a  work  intended  to 
serve  as  supplement  to  the  Philosophical  Transactions  up  to 
that  date.  In  1846.  at  the  suggestion  of  Harcourt,  the  Hypoth- 
esis of  Newton  was  again  printed  in  the  L.  E.  and  D.  Philo- 
sophical Magazine  (volume  xxix),  and  it  subsequently  appeared 
in  the  Appendix  to  the  first  volume  of  Brewster's  Memoirs  of 
Sir  Isaac  Newton,  in  1855. 

The  time  has  come  for  further  inquiries  into  the  science  of 
Newton,  and  T  shall  endeavor  to  show  that  a  careful  examina- 

*  Read  before  the  Cambridge  (England)  Philosophical  Society,  November  28, 
1881,  and  reprinted  from  its  Proceedings, 
f  L.  E.  and  D.  Philos.  Magazine,  III,  xxviii,  106  and  478;  also  ixix,  185. 


124 


T.  S.  Hunt — Celestial  Chemistry, 


tion  of  the  writings  of  our  great  Natural  Philosopher,  in  the 
light  of  the  scientific  progress  of  the  last  generation,  renders  still 
more  evident  the  wonderful  prevision  of  him  who  already,  two 
centuries  since,  had  anticipated  most  of  the  recent  speculations 
and  conclusions  regarding  cosmic  chemistry. 

As  an  introduction  to  the  inquiries  before  us,  and  in  order  to 
show  the  real  significance  of  the  speculations  of  Newton,  it 
will  be  necessary  to  review,  somewhat  at  length,  the  history  of 
certain  views  enunciated  almost  simultaneously  by  the  late  Sir 
Benjamin  Brodie,  of  Oxford,  and  the  present  writer,  and  subse- 
quently developed  and  extended  by  the  latter.  In  part  I  of 
his  Calculus  of  Chemical  Operations,  read  before  the  Royal 
Society,  May  3, 1866,  and  published  in  the  Philosophical  Trans- 
actions for  that  vear,  Brodie  was  led  to  assume  the  existence  of 
certain  ideal  elements.  These,  he  said  "though  now  revealed 
to  us  through  the  numerical  properties  of  chemical  equations 
only  as  implicit  and  dependent  existences,  we  cannot  but  surmise 
may  sometimes  become,  or  may  in  the  past  have  been,  isolated 
and  independent  existences^  Shortly  after  this  publication,  in  the 
spring  of  1867, 1  spent  several  days  in  Paris  with  the  late  Ilenri 
Sainte-Ciaire  Deville,  repeating  with  him  some  of  his  remarka- 
ble experiments  in  chemical  dissociation,  the  theory  of  which 
we  then  discussed  in  its  relations  to  Faye's  solar  hypothesis. 
From  Paris,  in  the  month  of  May,  I  went,  as  the  guest  of  Bro- 
die, for  a  few  days  to  Oxford,  where  I  read  for  the  first  time 
and  discussed  with  him  his  essay  on  the  Calculus  of  Chemical 
Operations,  in  which  connection  occurred  the  very  natural  sug- 
gestion that  his  ideal  elements  might  perhaps  be  liberated  in 
solar  fires,  and  thus  be  made  evident  to  the  spectroscope.  I 
was  then  about  to  give,  by  invitation,  a  lecture  before  the 
Royal  Institution  on  The  Chemistry  of  the  Primeval  Earth, 
which  was  delivered  May  31,  1867.  A  stenographic  report  of 
the  lecture,  revised  by  the  author,  was  published  in  the  Chem- 
ical News  of  June  21,  1867,  and  in  the  Proceedings  of  the 
Royal  Institution.  Therein,  I  considered  the  chemistry  of  neb- 
ulae, sun  and  stars  in  the  combined  light  of  spectroscopic 
analysis  and  Deville's  researches  on  dissociation,  and  con- 
cluded with  the  generalij^ation  that  the  "breaking-up  of  com 
pounds,  or  dissociation  of  elements,  by  intense  heat  is  a  principle 
of  universal  application,  so  that  we  may  suppose  that  all  the 
elements  which  make  up  the  sun,  or  ou"  planet,  would,  when  so 
intensely  heated  as  to  be  in  the  gaseous  condition  which  all 
matter  is  capable  of  assuming,  remain  uncombincd;  that  is  to 


say, 


would  exist  together  in 


the  state  of  chemical  elements; 
stellar  or  nebulous  masses  may 


whose  further  dissociation  in 

even  give  us  evidence  of  matter  still  more  elemental  than  that 

revealed  in  the  experiments  of  the  laboratory,  where  we  can 


7'.  S.  flwU — Celestial  Chemistry, 


125 


only  conjecture  the  compound  nature  of  many  of  the  so-called 
elementary  substances." 

The  importance  of  this  conception,  in  view  of  subsequent 
discoveries  iji  spectroscopy  and  in  stellar  chemistry,  has  been 
well  set  forth  by  Lockyer  in  his  late  lectures  on  Solar  Physics,* 
where,  however,  the  generalization  is  doscribod  as  having  been 
first  made  by  Brodie  in  1867.  A  similar  but  later  enunciation 
of  the  same  idea  by  Clerk-Maxwell  is  also  cited  by  Lockyer. 
Brodie,  in  fact,  on  the  6th  of  June,  one  week  after  my  own 
lecture,  gave  a  lecture  on  Ideal  Chemistry  before  the  Chemical 
Society  of  London,  published  in  the  Chemical  News  of  June 
14th,  in  which,  with  regard  to  his  ideal  elements,  in  further 
extension  of  the  suggestion  already  put  forth  by  him  in  the 
extract  above  given  from  his  paper  of  May  6,  1866,  he  says 
"  we  may  conceive  that  in  remote  ages  the  temperature  of 
matter  was  much  higher  than  it  is  now,  and  that  these  other 
things  [the  ideal  elements]  existed  in  the  state  of  perfect  gases — 
separate  existences — uncombined."  He  further  suggested,  from 
spectroscopic  evidence,  that  it  is  probab' ^  that  "we  may  one 
day,  from  this  source  have  revealed  to  us  independent  evidence 
of  the  existence  of  these  ideal  elements  in  the  sun  and  stars." 

During  the  months  of  June  and  July,  1867,  I  was  absent  on 
the  continent,  and  this  lecture  of  Brodie's  remained  wholly 
unknown  to  me  until  its  republication  in  1880,  in  a  separate 
form,  by  its  author,f  with  a  preface,  in  which  he  pointed  out 
that  he  had  therein  suggested  the  probable  liberation  of  his 
ideal  elements  in  the  sun,  referring  at  the  Siime  time  to  his 
paper  of  1866,  from  which  we  have  already  quoted  the  only 
expression  bearing  on  the  possible  independence  of  these  ideal 
elements  somewhere  in  time  or  in  space. 

The  above  statements  are  neccvssary  in  order  to  explain  why 
it  is  that  I  have  made  no  reference  to  Sir  Benjamin  Brodie  on 
the  several  occasions  on  which,  in  the  interval  between  1867 
and  the  present  time,  I  have  reiterated  and  enforced  my  views 
on  the  great  significance  of  the  hypothesis  of  celestial  dissocia- 
tion as  giving  rise  to  forms  of  matter  more  elemental  than  any 
known  to  us  in  terrestrial  chemistry.  The  conception,  as  at 
first  enunciated  in  somewhat  different  forms  alike  by  Brodie 
and  myself,  was  one  to  which  we  were  both  naturally,  one 
might  say  inevitably,  led  by  different  paths  from  our  respective 
fields  of  speculation,  and  which  each  might  accept  as  in  the 
highest  degree  probable,  and  make,  as  it  were,  his  own. 
I  write,  therefore,  in  no  spirit  of  invidious  rivalry  with  my  hon* 
ored  and  lamented  friend,  but  simply  to  clear  myself  from  the 
charge,    which    might   otherwise   be   brought  against  me,    of 


*  Nature,  August  25,  1881,  vol.  xxiv,  p.  396. 
f  Ideal  Chemistry,  a  Lecture.     Macmillan,  1880. 


H* 


126 


T.  S.  Hunt — Celestial  Chemistry. 


having  on  viirioas  occasions  within  the  past  fourteen  years, 
put  forth  and  enlarged  u[)()n  this  coneepiion  without  mention- 
ing Sir  Benjamin  liroiiie,  whose  only  publication  on  the  subject, 
so  far  as  I  am  aware,  was  his  lecture  of  1867,  unknown  to  me 
until  its  reprint  in  1880. 

It  was  at  the  grave  of  Priestley,  in  1874,  that  T  for  the  second 
time  considered  t!ie  doctrine  of  celestial  dissociation,  comtnenc- 
ing  with  an  account  of  the  hypothesis  put  for\,-ard  by  F.  W. 
Clarke,  of  Cincinnati,  in  January,  1878,"''"  to  explain  the  grow- 
ing complexity  which  is  observed  when  we  compare  the  spectra 
of  the  white,  yellow  and  red  stars;  in  which  he  saw  evidetice  of 
a  progressive  evolution  of  chemical  species,  by  a  stoichiogenic 
process,  from  more  elemental  forms  of  matter.  I  then  referred 
to  the  further  development  of  this  view  by  Lockyer  in  his  com- 
munication to  the  French  Academy  of  Sciences  in  November 
of  the  same  year,  v\dierein  he  conneG:;ed  the  successive  appear- 
ance in  celestial  bodi-^s  of  chemical  species  of  higher  and  higher 
vapor-densities  with  the  speculations  of  Dumas  and  Pettenkofer 
as  to  the  composite  nature  of  the  chemical  elements. f  I  then 
quoteil  from  my  lecture  of  1867  the  language  already  cited,  to 
the  effect  that  dissocnition  by  intense  heat  in  stellar  worlds 
might  give  us  more  elemental  forms  of  matter  than  any  known 
on  earth,  and  further  suggested  that  the  gn'cn  line  in  the  spec- 
trum of  the  solar  corona,  which  had  been  supposed  to  indicate 
a  hitherto  unknown  substance,  may  be  due  to  a  "more  elemen- 
tal form  of  matter,  which,  though  not  seen  in  the  nebu  as,  is 
liberated  by  the  intense  heat  of  the  solar  sphere,  and  may  possi- 
bly correspond  to  the  primary  matter  conjectured  by  Dumas, 
having  an  equivalent  weight  one-fourth  that  of  hydrogen." 
The  suggestion  of  Lavoisier,  that  "hydrogen,  nitrogen,  and 
oxygen,  with  heat  and  light,  might  be  regarded  as  simpler 
forms  of  matter  from  which  all  others  are  derived,"  was  also 
noticed  in  connection  with  the  fact  that  the  nebuke,  which  we 
conceive  to  be  condensing  into  suns  and  planets,  have  hitherto 
shown  evidences  only  of  the  presence  of  the  first  two  of  these 
elements,  which,  as  is  well-known,  make  up  a  large  part  of  the 
gaseous  envelope  of  our  planet,  in  the  forms  of  air  and  aqueous 
vapor.  With  this,  I  connected  the  hypothesis  that  our  atmos- 
phere and  ocean  are  but  portions  of  the  universal  medium 
which,  in  an  attenuated  form,  fills  the  interstellary  spaces;  and 
further  suggested  as  "a  legitimate  and  plausible  speculation," 
that  "those  same  nebuloe  and  their  resulting  worlds  may  be 
evolved  by  a  process  of  chemical  condensation  from  this  univer- 
sal atmosphere,  to  which  they  would  sustain  a  relation  some- 

♦Clarke,  'Evolution  and  the  Spectroscope,"  Popular  Science  Monthly,  New 
York,  vol.  ii,  p.  82. 

f  Lockyer,  Comptes  Rendus,  November  3,  1873. 


T.  S.  Hunt — Celestial  Chemistry. 


127 


what  analogous  to  that  of  clouds  and  rain  to  the  aqueous  vapor 
around  us."''* 

These  views  were  reiterated  in  the  prefnce  to  a  second  edition 
of  my  Clietnical  and  Geoh)gical  Essays,  in  1878,  and  again  hyl'ore 
the  Britisli  Association  for  the  Advancement  of  Science  at 
Dubhn,f  and  before  tiic  French  Academy  of  Sciences  in  the 
same  year.ij:  They  were  still  further  developed  in  an  essay  on 
the  Chemical  and  (ieological  liclaiions  of  the  Atmosphere, 
published  in  this  Journal  for  May,  1880,  in  which  attention  was 
called  to  the  important  contribution  to  the  subject  by  Mr. 
Lockyer  in  his  ingenious  and  beautiful  spectroscopic  studies, 
the  results  of  which  are  embodied  in  his  "Dis(!ussion  of  the 
Working  Hypothesis  that  the  so-called  Klenients  are  Cotn[)ound 
Bodies,"  communicated  to  the  Royal  Society,  pccember  12, 
1878.  It  was  then  remarked  that  the  already  noticed  "specu- 
lation of  Lavoisier  is  really  an  anticipation  of  that  view  to 
which  spectroscopic  study  has  led  the  chemists  of  to-day  ;"  while 
it  was  said  that  the  hypothesis  put  forth  by  the  writer  in  1874, 
"  which  seeks  for  a  source  of  the  nebulous  mattei-  itself,  is  per- 
haps a  legitimate  extension  of  the  nebular  hypothesis." 

To  show  the  connection  of  the  above  views  with  the  philoso- 
phy of  Newton,  it  now  becomes  necessary  to  give  som»  account 
of  the  conception  of  the  universal  distribution  of  matter  through- 
out space,  both  as  regards  its  dynamical  relations  and  its  chem- 
ical composition.  Passing  over  the  speculations  of  the  Greek 
physiologists,  we  come  to  the  controversies  on  this  subject  in 
the  seventeenth  century,  and  find,  in  apparent  opposition  to  the 
plenum  maintained  by  Descartes  and  his  followers,  the  teaching 
of  Newton  that  "the  heavens  are  void  of  all  sensible  matter. 
This  statement  is,  however,  qualified  elsewhere  by  iiis  assertion, 
that  "to  make  way  for  the  regular  and  lasting  movements  of 
the  planets  and  comets,  it  is  necessary  to  empty  the  heavens  of 
all  matter,  except  perhaps  some  very  thin  vapors,  steams  and 
effluvia  arising  from  the  atmospheres  of  the  earth,  planets  and 
comets,  and  from  such  an  exceedingly  rare  etherial  medium  as 
we  have  elsewhere  described,"  etc.  {Optics^  Book  iii.  Query  28). 

In  order  to  understand  fully  the  views  of  Newton  on  this 
subject,  it  is  necessary  to  compare  carefully  his  various  utter- 
ances, including  the  Hypothesis,  in  1675,  the  first  edition  of 
the  Piindpia,  in  1687,  the  second  edition,  in  1713,  and  the  va^ 
rious  editions  of  the  Optics.  This  work  appeared  in  1704,  the 
third  book,  with  its  a[)pended  queries,  having,  according  to  its 
author's  preface,  been  "put  together  out  of  scattered  papers 

*  A  Century's  Progress  in  Theoretical  Chemistry,  being  an  address  at  Northum- 
berland, Penu..  July  31,  1874;  Amcr.  Chemist,  vol.  v,  pp.  46-61,  and  Pop.  Scir 
ence  Monthly,  vi,  p.  420. 

f  Nature,  Aug.  29.  ISIS,  vol.  xviii,  p.  475. 

X  Comptea  Rendus,  Sept.  23,  1878,  vol.  xxxviii,  p.  452. 


128 


T.  S.  Hunt — Celestial  Chemistry. 


8uV)aeqnent  to  the  publicntion  of  the  first  edition  of  the  Pi'nei- 
pia.  Tlic  Latin  translation  of  t,h(!  O/itirs,  by  Dr.  Clarke,  which 
was  published  in  17(H5,  and  the  second  English  edition,  in  1718, 
contain  successive  additions  to  these  queries,  which  are  indi- 
cated in  the  notes  to  Ilorsley's  edition  of  the  works  of  New- 
ton, and  are  important  iti  this  connection.  From  a  collation  ol 
all  these,  we  learn  how  the  conceptions  of  the  Hypothesis  took 
shape,  were  reinforced,  and  in  great  part  incorporated  in  the 
Principia. 

In  the  TTypothesis,  ho  imagines  "an  etherial  medium  much 
of  the  same  constitution  with  air,  but  far  rarer,  subtler,  and 
more  elastic."  **But  it  is  not  to  be  supposed  that  this  medium 
is  one  uniform  matter,  but  composed  partly  of  the  main  phleg- 
matic body  of  ether,  f)artly  of  other  various  etherial  spirits, 
much  after  the  manner  that  air  is  compounded  of  the  phleg- 
matic body  of  air  intermixed  with  various  vn[)ors  and  exnala- 
tions."  l^ewton  further  suggests  in  his  Hypothesis  that  this 
complex  spirit  or  ether,  which,  by  its  elasticity,  is  extended 
throughout  all  space,  is  in  continual  movement  and  interchange. 
"  J'or  nature  is  a  perpetual  circulatory  worker,  generating  fluids 
out  of  solids,  and  solids  out  of  fluids,  fixed  things  out  of  vola- 
tile, and  Volatile  out  of  fixed,  subtile  out  of  gross,  and  gross  out 
of  subtde;  some  things  to  ascend  and  make  the  upper  terres- 
trial juices,  rivers,  and  the  atmosphere,  and  by  consequence 
others  to  descend  for  a  requital  to  the  former.  And  as  the 
earth,  so  perhaps  may  the  sun  imbibe  this  spirit  copiously,  to 
conserve  nis  shining,  and  keep  the  planets  from  receding  far- 
ther from  him;  and  they  that  will  may  also  suppose  that  this 
spirit  affords  or  carries  with  it  thither  the  solary  fuel  and  ma- 
terial principle  of  life,  and  that  the  vast  etherial  spaces  between 
us  and  the  stars  are  for  a  sufficient  repository  for  this  food  of 
the  sun  and  planets." 

The  lano;uage  of  this  last  sentence,  in  which  his  late  biogra- 
pher, Sir  David  Brewster,  regards  Newton  as  "amusing  himself 
with  the  extravagance  of  his  speculations,"  at  which  "  we  may 
be  allowed  to  smile/'*  was  not  apparently  regarded  as  unrea- 
sonable by  its  author  when,  more  than  ten  years  later,  he  quoted 
it  in  the  postscript  of  his  letter  to  Halley,  dated  Cambridge, 
June  20,  1686.  The  views  therein  contained,  with  the  single 
exception  of  the  suggestion  regarding  gravitation,  have  not 
wanted  advocates  in  our  own  time,  and  many  of  them  were 
embodied  in  the  Principia,  which  Newton  was  then  engaged  in 
writing. 

But  this  was  not  all :  Newton  saw  in  the  cosmic  circulation 
and  the  mutual  convertibility  of  I'are  and  dense  forms  of  matter 
a  universal  law,  and  rising  to  a  still  bolder  conception,  which 

*  Brewster's  Memoirs  of  Newton,  vol.  i,  pp.  121  and  404. 


T.  S,  Hunt — Celestial  Chemislry. 


189 


completes  bis  Hypothesis  of  the  Universe,  ndds:  "Perhnps  the 
whole  frame  of  nature  may  he  nothing  hut  various  contextures 
of  some  certain  cthorinl  spirits  or  vapors,  condonscd,  as  it  were, 
by  precipitation,  much  alter  the  same  manner  that  vapors  are 
condensed  into  water,  or  exhalations  into  grosser  substances, 
though  not  so  easily  condensible ;  and  after  corxh^nsation 
wrought  into  various  forms,  at  first  by  the  immediate  hand  of 
the  Creator,  and  ever  since,  by  the  power  of  nature,  which,  by 
virtue  of  the  command  'increase  and  multiply,'  became  a  com- 
plete imitator  of  the  copy  set  her  by  the  great  Protoplast. 
Thus,  perhaps  nuiy  all  things  be  originated  from  ether." 

If  now  we  look  to  the  third  book  of  the  Principia,  we  shall 
find  in  proposition  41  the  remarkable  chemical  argument  by 
which  Newton  was  led  to  regard  the  interstellary  ether  aa 
affording  "the  material  princij)le  of  life'"  and  "the  food  of 
planets."  Considering  the  exhalations  from  the  tails  of  comets, 
he  supposes  that  the  vapors  thus  derived,  being  rarified,  dilated, 
and  spread  through  the  whole  heavens,  are  by  gravity  brought 
within  the  atmospheres  of  the  planets,  where  they  serve  for  the 
support  of  vegetable  life.  Inasmuch,  moreover,  as  all  vegeta- 
tion is  supported  by  fluids,  and  subsequently,  by  decay  is,  in 
part,  changed  into  solids,  by  which  the  mass  of  the  earth  is 
augmented,  he  concludes  that  if  these  essential  matters  were 
not  supplied  from  some  external  source,  they  must  continually 
decrease,  and  at  last  fail.  This  vital  and  subtile  part  of  our 
atmosphere,  so  important,  though  small  in  amount,  he  then 
supposed  might  come  from  the  tails  of  comets,* 

This  appeared  in  the  first  edition  of  the  Prindpia,  in  1687. 
It  was  not  until  later  that  the  conception  of  exhalations  from 
other  celestial  bodies  took  shape  in  the  mind  of  Newton,  as 
we  may  learn  from  the  Optics.  Thus,  in  the  first  edition  of  this 
work,  in  Query  11,  the  sun  and  fixed  stars  are  spoken  of  as 

*"  Vapor  enirn  in  spatiis  illis  liberrimi.s  perpetu6  rarescit,  iic  dilatnlur.  QuA 
ratione  fit  ut  cauda  omnia  ad  extremitatcm  Huperioiom  latior  sit  qnam  juxta  ca- 
pita cometae.  VA  aiitem  rarefactione  vaporem  per|)etn6  dilatatum  ditJ'undi  tan- 
dem et  spargi  par  coelos  univoraos,  doindo  paulatim  in  planotas  per  gra  vita  tern 
suani  attrahi  ot  cum  eornni  atmosphaoris  rnisceri,  rationi  conHontaneum  videlnr. 
Nam  quemadmodnm  maria  ad  conBtitntionom  Torrae  hujiis  omnino  requirnntnr, 
idque  ut  ex  iis  per  caiorem  Solis  vaporos  cDpiose  satis  excitentur,  qui  vel  in  nnboa 
coacti  decidant  in  pluviia,  et  Terrani  oninem  ad  procroalioiiem  vegetabiiiuni  irri- 
gent  et  nutriant;  vol  in  frigidis  montiuni  verticibus  condonsati  (ut  aiiqui  cum  ra- 
tione philosophantur)  decurrant  in  fontca  ei;  fliimina:  sic  ad  conservationem  ma- 
rium  et  huniorum  in  planetis  rctpiiri  videntur  cometae,  ex  quorum  exlialationibus 
et  vaporibus  condensatis,  quicqnid  liquoris  per  vegetationem  et  putrefactionem 
consumitur  ct  in  Terram  aridam  oonvortitur,  continuo  supplori  et  refici  poasit. 
Nam  vegetabilia  omnia  ex  liciuoribus  omnino  creacunt,  dcin  magna  ex  parte  in  Ter- 
ram aridam  per  putrefactionem  abeimt,  et  limus  ex  liquoril)us  putrefactis  perpetu6 
decidit.  Hinc  moles  Terrae  aridae  indies  augetur,  et  hquorea,  niai  aliunde  augmsn- 
tum  sumerent,  perpetu6  decresere  deberent,  ac  tandem  deficere.  Porro  suapicor 
splritum  ilium,  ([ui  aeris  noatri  jmrs  minima  eat,  aed  aubtillissima  et  optima,  et  ad 
rerum  omnium  vitam  requiritur,  ex  cometis  praecipue  venire." — Newton,  Frincipia, 
lib.  Ill,  prop.  XLi. 


130 


T.  S.  Hunt — Celestial  ChemiMry. 


great  earths,  intensely  heated,  and  surrounded  with  dense  at- 
mospheres which,  by  their  weight,  condense  the  exhalations 
arising  from  these  hot  bodies.  To  this  Query  is  added,  in 
IVOG,  the  suggestion  that  the  weight  of  such  an  atmosphere 
"may  hinder  the  globe  of  the  sun  from  being  diminished  ex- 
cept by  the  emission  of  light;"  while  in  the  second  English 
edition,  in  1718,  we  find  a  further  addition,  in  the  words  "and  a 
very  small  quantity  of  vapors  and  exhahitions.  A  similar 
change  of  view  appears  in  the  Query  now  numbered  28,  wherein 
we  read  of  "places  [almost]  destitute  of  matter,"  and  also  that 
"the  sun  and  planets  gravitate  towards  each  other  without 
[dense]  matter  between."  In  these  quotations,  the  two  words 
in  brackets  are  wanting  in  the  edition  of  1706,  and  first  appear 
in  that  of  1718;  while  the  language  which  we  have  in  a  pre- 
vious page  quoted  from  this  same  Query  is  found  in  the 
edition  of  170().' 

The  Queries  now  numbered  17-24,  appeared  for  the  first 
time  in  the  edition  of  1718,  and  herein  we  find,  in  18,  the  ethe- 
rial  medium  spoken  of  as  being  "by  its  elastic  force  expanded 
through  all  the  heavens"  Of  this  medium,  "which  fills  all 
spiice  adequately,"  he  asks,  "  may  not  its  resistance  be  so  small 
as  to  be  inconsiderable,"  and  scarcely  to  make  any  sensible  al- 
teration in  the  movements  of  the  planets?*  This  complex 
ether  of  the  interstellary  space  was  thus,  in  the  opinion  of  New- 
ton, made  up  in  part  of  matter  common  to  the  planetary  and 
stellar  atmospheres,  the  origin  and  importance  of  which  is  con- 
cisely stated  in  the  paragraph  which  appears  for  the  first  time 
in  1713,  in  the  second  edition  of  the  Principia,  in  the  third 
book,  at  the  end  of  proposition  42,  here  much  augmented.  In 
this  statement,  which  serves  to  supplement  and  complete  that 
already  made  in  1H87,  in  proposition  41,  we  read,  that  the  va- 
pors which  arise  alike  from  the  sun,  the  fixed  stars  and  the  tails 
of  comets,  may  by  gravity  fall  into  the  atmospheres  of  the 
planets,  and  there  be  condensed,  and  f>ass  into  the  form  of  salts, 
sulphurs,  {id  est,  combustible  matters,)  tinctures,  clay,  sand, 
coral  and  other  terrestrial  substances.f 

The  concef)tion  of  Newton,  who,  while  rejecting  alike  the 
plenum  of  the  Cartesians,  with  its  vortices,  and  an  absolute  vac- 
uum, imagined  space  to  be  filled  with  an  exceedingly  atten- 
uated matter,  through  which  a  free  circulation  of  gaseous  .sub- 
stances might  take  place  between    distant  worlds,  has  found 

*  Compare  this  with  Prop,  x,  Bool<  III  of  the  Prineipia. 

f  "  Vapores  autcm,  qui  ex  Sole  et  steUis  fixis  et  caudis  cometarum  ..  /tiir,  in- 
cidere  popsunt  per  gravitatem  suam  in  atmosphaeras  planetariim.  et  ibi  comiensari 
et  convert!  in  iiquam  et  spiritos  lunnidos,  et  siibinde  per  leiitem  vialorom  in  sales, 
et  siilphura.  et  tinoturas.  et  limum,  et  lutem.  et  arpillam,  et  arenam,  et  lapides,  et 
roralla,  et  substantias  alias  terrestres  paulatim  niigrare." — Newton,  Prineipia,  lib. 
111.  prop.  XLIl. 


T.  S.  Hunt — Celestial  Chemistry. 


131 


favor  among  modern  thinkers,  who  seem  to'have  been  ignorant 
of  his  views.  Sir  William  Grove  in  18-12,  suggested  that  the 
medium  of  light  and  heat  may  be  "  a  universally  dif- 
fused matter,"  and  subsequently,  in  1813,  in  the  chapter  on 
Light,  in  his  Essay  on  the  Correlation  of  Physical  Forces,  con- 
cluded with  regard  to  the  atmospheres  of  the  sun  and  the  plan- 
ets, that  there  is  no  reason  "  why  these  atmospheres  should  not 
be,  with  reference  to  each  other,  in  a  state  of  equilibrium. 
Ether,  which  term  we  may  apply  to  the  highly  attenuated  mat- 
ter existing  in  the  interplanetary  spaces,  being  an  expansion  of 
some  or  all  of  these  atmospheres,  or  of  the  more  volatile  por- 
tions of  them,  would  thus  furnish  matter  for  the  transmission 
of  the  modes  of  motion  which  we  call  light,  heat,  etc. ;  and  pos- 
sibly minute  portions  of  the  atmospheres  may,  by  gradual  accre- 
tions and  subtractions,  pass  from  planet  to  planet,  forming  a 
link  of  material  communication  between  the  distant  monads  of 
the  universe."  Subsequently,  in  his  address  as  President  of 
the  British  Association  for  the  Advancement  of  Science,  in 
1866,  Grove  further  suggested  that  this  diffused  matter  may  be- 
come a  source  of  solar  heat,  "  inasmuch  as  the  sun  ma}^  con- 
dense gaseous  matter  as  it  travels  in  space,  and  so  heat  may  be 
produced." 

Humboldt,  also,  in  his  Cosmos,  considers  the  existence  of  a 
resisting  medium  in  space,  and  says  "of  this  impeding  ether- 
ial  and  cosmical  matter,"  it  may  be  supfiosed  that  it  is  in  mo- 
tion, that  it  gravitates,  notwithstanding  its  great  tenuity,  that  it 
is  condensed  in  the  vicinity  of  the  great  mass  of  the  sun,  and 
that  it  may  include  exhalations  from  comets  ;  in  which  connec- 
tion he  quotes  from  the  42nd  f)roposition  of  the  third  book  of 
the  Principia.  He  further  speaks  comprehensively  of  "the  va- 
porous matter  of  the  incommensurable  regions  of  space, 
whether,  scattered  without  definite  limits,  it  exists  as  a  cosmical 
ether,  or  is  condensed  in  nebulous  masses  and  becomes  com- 
pri.qed  among  the  agglomerated  bodies  of  the  universe."*  Hum- 
boldt also  cites  in  this  connection  a  suggestion  made  by  Arago 
in  the  Annuaire  du  Bureau  des  Longitudes  for  1812,  as  to  the 
possibility  of  determining,  by  a  comparison  of  its  refractive 
power  with  that  of  terrestrial  gases,  the  density  of  "  the  ex- 
tremely rare  matter  occupying  tlie  regions  of  space. "f 

In  1851,  Sir  William  Thomson  published  his  note  on  the 
Possible  Density  of  the  Luminiferous  Ether,:}:  wherein  he  re- 
marks "  thai  there  must  be  a  medium  of  material  communica- 
tion throughout  space  to  the  remotest  visible  body,  is  a  funda- 
mental conception  of  theundulatory  theory  of  liglit.     Whether 

*  Cosmos,  Otte's  translation,  Harper's  ed.,  vol.  i,  pp.  82,  86. 

5  Ibid.,  vol.  iii,  p.  41*. 
Trans.  Roy.  Soc.  Erlinbnrgh,  vol.  xxi,  part  1 ;  and  Phil.  Mag.,  1855,  vol.  ix, 
p.  36. 


132 


7!  S.  Hunt — Celestial  Ghemislry. 


or  no  this  medium  is  (as  appears  to  me  most  probable)  a  con- 
tinuation of  our  own  atmosphere,  its  existence  cannot  be  ques- 
tioned." He  then  attempts  to  fix  an  inferior  limit  to  the  den- 
sity of  the  luminiferous  medium  in  interplanetary  space  by  con- 
sidering the  mechanical  value  of  sunlight,  as  deduced  from 
the  value  of  solar  radiation  and  the  mechanical  equivalent  of 
the  thermal  unit.  He  concludes  "  that  the  luminiferous  me- 
dium is  enormously  denser  than  ihe  continuation  of  the  terres- 
trial atmosphere  would  be  in  'nterplantury  space  if  rarified  ac- 
cording to  Boyle's  law  always,  and  if  the  earth  were  at  rest  in 
a  state  of  constant  temperature,  with  an  atmosphere  of  the  act- 
ual density  at  its  surface."  The  earth  itself  in  moving  through 
space  "cannot  displace  less  than  250  pounds  of  matter." 

In  1870,  W.  Mattieu  Williams  published  his  very  ingenious 
work  entitled  The  Fuel  of  the  Sun,  in  which,  apparently  with- 
out any  knowledge  of  what  had  been  written  before  with  regard 
to  an  interstellary  medium,  he  attempts  to  find  therein  the 
source  of  solar  heat — the  "solary  fuel  "  of  Newton.  To  quote 
his  own  language,  "  the  gaseous  ocean  in  which  we  are  im- 
mersed is  but  a  portion  of  the  infinite  atmosphere  that  fills  the 
whole  solidity  of  sf)ace,  that  links  together  all  the  elements  of 
the  universe,  and  diffuses  among  them  light  and  heat,  and  all 
the  other  physical  and  vital  forces  which  heat  and  light  are 
capable  of  generating"  (loc.  cit.  p.  5). 

Since  the  days  of  Newton,  however,  no  one  had  hitherto  con- 
sidered the  interstellary  matter  from  a  cheuiical  point  of  view. 
In  1874,  as  already  shown,  the  writer  had,  in  extension  of  the 
conception  of  Humboldt  that  its  condensation  gives  rise  to 
nebulas,  ventured  the  suggestion  that  from  an  etherial  medium 
having  the  same  composition  as  our  own  atmosphere,  the  chemi- 
cal elements  of  the  sun  and  the  planets  have  been  evolved,  in 
accordance  with  the  views  of  Brodie,  Clarke,  and  Lockyer,  by  a 
stoichiogenic  process  ;  so  that  in  the  language  of  Newton's  Hy- 
pothesis, "all  things  may  be  originated  from  ether." 

It  was  not,  however,  until  1878,  that,  from  a  consideration  of 
the  chemical  processes  which  have  gone  on  at  the  earth's  sur- 
face within  recorded  geological  time,  I  was  led  to  another  step 
in  this  inquiry.  That  all  the  de-oxidized  carbon  found  In  the 
earth's  crust  in  the  forms  of  coal  and  graphite,  as  well  as  that 
existing  in  a  diffused  state,  as  bituminous  or  carbonaceous  mat- 
ter, has  come,  through  vegetation,  from  atmospheric  carbonic  acid, 
appears  certain.  To  the  same  source  we  must  ascribe  the  carbonic 
acid  of  all  the  limestones  which,  since  the  dawn  of  life  on  our 
earth,  have  been  deposited  from  its  waters.  It  is  through  the 
sub-aerial  decay  of  crystalline  silicated  rocks,  and  the  direct 
formation  of  carbonate  of  lime,  or  of  carbonates  of  magnesia 
and  alkalies  which  have  reacted  on  the  calcium-salts  of  the  pri 


T.  S.  Hunt — Celestial  Chemistry. 


188 


)  a  con- 
)e  ques- 
,he  den- 
by  con- 
;d  from 
alent  of 
)us  n»e- 
B  terres- 
ified  ac- 
t  rest  in 
the  act- 
through 
I) 

genious 
ly  with- 
11  regard 
rein  the 
'o  quote 
are  im- 
fills  the 
nents  of 
and  all 
ght   are 

srto  con- 
of  view, 
n  of  the 
rise  to 
medium 
echemi- 
)lved,  in 
rer,  by  a 
3n's  Hy- 

I'ation  of 
th's  sur- 
her  step 
d  in  tlie 

as  that 
)us  mat- 
micacid, 
carbonic 
3  on  our 
)ugh  the 
le  direct 
uagnesia 

the  pri 


meval  ocean,  that  all  limestones  and  dolomites  have  been  gen- 
erated. These,  apart  from  the  coaly  matter,  hold,  locked  up 
and  withdrawn  from  the  aerial  circulation,  an  amount  of  car- 
bonic acid  which  may  be  probably  estimated  at  not  Jess  than 
200  atmospheres  equal  in  weight  to  our  own.  That  this 
amount,  or  even  a  thousandth  part  of  it,  could  have  existed  at 
any  one  time  in  our  terrestrial  atmosphere  since  the  beginning 
of  life  on  our  planet  is  inconceivable,  and  that  it  could  be  sup- 
plied from  the  earth's  interior  ia  an  hypothesis  equally  un- 
tenable. 

I  was  therefore  led  to  admit  for  it  an  extra-terrestrial  source, 
and  to  maintain  that  the  carbonic  acid  has  thence  gradually 
come  into  our  atmosphere  to  supply  the  deficiencies  created  by 
chemical  processes  at  the  earth's  surface.  Since  similar  pro- 
cesses are  even  now  removing  from  our  atmosphere  this  indis- 
pensable element,  and  fixing  it  in  solid  forms,  it  follows  that 
except  volcanic  agency,  which  can  only  restore  a  portion  of 
what  was  primarily  derived  from  the  atmosphere,  there  are  on 
earth,  besides  organic  decay,  only  the  artificial  processes  of  hu- 
man industry  which  can  furnish  carbonic  acid  ;  so  that  but 
for  a  supply  of  this  gas  from  the  interstellary  spaces  now,  as  in 
the  past,  vegetation,  and  consequently  animal  life  itself,  would 
fail  and  perish  from  the  earth,  for  want  of  this  "  food  of  planets." 

Such  were  the  conclusions,  based  on  an  induction  from  the 
facts  of  modern  chemistry  and  geology,  which  I  enunciated  in 
my  papers  in  1878  and  1880,  already  quoted  in  the  first  part  of 
this  essay.  I  was  at  that  time  unacquainted  with  the  Hypothe- 
sis of  Newton,  and  with  his  remarkable  reasoning  contained  in 
the  41st  proposition  of  the  third  book  of  the  Principia^  in  which 
he,  so  far  as  was  possible  with  the  chemical  knowledge  of  his 
time,  anticipated  my  own  argument,  and  showed  how  and  in 
what  manner  the  interstellary  ether  may  really  afford  the  "food 
of  planets,"  and,  in  a  sense,  "the  material  principle  of  life." 

I  have  thus  endeavored  to  bring  before  the  Philosophical 
Society  of  Cambridge,  a  brief  history  of  the  development  of 
this  conception  of  an  interstellary  medium,  and  to  show  that 
the  thought  of  two  centuries  has  done  little  more  than  confirm 
the  almost  forgotten  views  of  Newton.  It  is  with  feelings  of 
peculiar  gratification  that  I  have  been  able  to  indite  these  pages 
within  the  very  walls  of  the  college  in  which  our  great  phil- 
osopher lived  and  labored,  and  where,  combining  all  the  science 
of  his  time  with  a  foresight  which  seems  well-nigh  divine,  he 
was  enabled,  in  the  words  of  the  poet,  "to  think  again  the 
great  thought  of  the  creation." 


